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Ilrsrrsn S'rarns ArnNr @rlrrc GEORGE E. MEYER, OF NEYV YORK, N. Y.,ASSIGNOR TO THE DE LA VERGNE REERIGERATIN G MACHINE COMPANY, OF SAMEPLACE.

ART OF REFRIGERATION BY COMPRESSION AND EXPANSION F GASES.

SPECIFICATION forming part of Letters Patent No. 371,779, dated October18, 1887.

Application filed April 12, 1887. Serial No. 234,533. (No model.)

To all whom, it may concern:

Be it known that I, GEORGE F. MEYER, of the city, county, and State ofNew York, have invented a new and useful Improvement in the Art ofRefrigeration by Compression and Expansion of Gases, or compressing andexpanding gases for purposes of refrigeration when such gases arecompressed in contact with or presence of lubricating-liquids.

In all of the known processes in which alubricating liquid is employedthe gas is compressed in some kind of a pump to which liquid issupplied, and this liquid,afterbeing discharged from the pump inconnection with the 1 5 compressed gas, is separated mechanically fromthe gas or the liquefied gas and returned to the pump. in some of theseprocesses the oil is cooled after leaving the pump and before itisreturned to it. In others the oil is not cooled 23 prior to its returnto the pump. In some of these processes the oil is kept undersubstantially the pressure at which it left the pump until it returns toit. In others the oil is relieved to a greater or loss extent from press25 ure after leaving and before it is returned to the pump. In some ofthese processes the oil is'injected into the pump after thesuctionstroke thereof is completed; in others during the suction-stroke;in still others during the compression stroke, and in some instancesduring both the compression and the suctionstroke. The oil is alsosometimes admitted or forced into the compressionpump in measuredquantities, and sometimes through a simple 5 pipe controlled by a cock.In some of these processes the oil is cooled in the presence of gas; inothers after it has been separated mechanically from the gas. v

My improvement is applicable to any 0f 40 these processes, and requires,in order to work it out fully, first, a compressingpump; second, acondenser; third, an expansion-coil or its equivalent; fourth, aseparator or separating tank or tanks for separating oil from gas me- 5chanically; fifth, necessary connections of these parts, so thateirpanded gas may be returned to the compressing pump and that oildischarged from the pump may be returned thereto, all these parts beingsuch as are well known and usually employed in refrigerating apparatus.In addition to these parts or subdivisions of a complete apparatus thereis needed for carrying out my improvement some ll'lGitllS- -SllCll asajaeketed kettle, orsteam-coil,

or their substitutes or equivalents lorhcating 5 the oil after it hasbeen wholly or partially mechanically separated from the gas, and duringits progress from the discharge-valves of the compressingpump and beforeit returns or is returned to the pump again, and some proper connectionfrom the cavity in which the oil is heated to the pressure side of theapparatus.

1 use the word oil in this description and specification as includingand defining any of 6 the liquids and their equivalents now em ployed inrefrigerating processes for the purpose of filling up clearances incompressionpumps and preventing leakage of pistons, piston-rods, valves,&c., and the word gas as including and defining all the various kinds ofgas applicable for refrigerating purposes by compressing them and thenpermitting them.

to expand.

In such processes the oil takes up in the pump more or less of the gaswhich is being compressed and retains more or less of such gas after theoil has been expelled or discharged from the pump. If the oil. duringits progress from the discharge-valves of the pump until its returnthereto has the pressure upon it relieved, the theory is that some gasthen escapes from the oi., said gas escaping not to waste, but into thesuction or expansion side of the apparatus, whence the gas is returnedto the compressing-pump. If the oil be kept substantially underthepressure at which it left the compressing-pump and until its returnthereto, the theory is that the gas in the oil escapes in the pump whenthe presso ure in the pump is less than that of the entering oil, andthat this gas thus escaping cools the pump and also enables it todeliver at each stroke more gas than it would if the oil contained nogas at all, or less gas than was due to'the pressure under which the oilwas discharged from the pump. In both these ways of workingrefrigerating apparatus, however, the gas which escapes from. the oileither in the pump itself or into the suction or expanrco sion side ofthe apparatus must be recompressed,because in all known forms ofrefrigerating apparatus the gas circulates throughout the wholeapparatus and none of it is permitted to escape into the outer air towaste.

Now it is awell-known fact that the oil will, other things being equal,hold more gas at a high pressure than at a low one, and that it will,other things being equal, hold more gas at a low temperature than a highonethat is, if oil containing absorbed or mechanicallymixed therein acertain quantity of gas be heated, then the oil will part with aquantity, more or less, of this gas even if the pressure be not reduced.It is further known to those using the well-known processes, that themechanical separation of the oil from the gas in separating-tanks, ortheir substitutes for the purpose, is by no means perfect,and that theoil usually contains gas mechanically mixed therewith. A considerationof these facts has led me to this invention, and it consists in anaddition to the usual processes, whereby the oil,after being wholly orpartially mechanicall y separated from the gas, as usual, is heated sothat some of the absorbed and contained gas is to a greater or lessextent expelled therefrom and delivered into the pressure side of theapparatus. This heating takes place after the oil has been ejected fromthe pump and prior to its return thereto, and after the oil has beenwholly or partially mechanically separated, as usual,from the compressedgas, and I prefer to separate the oil mechanically from the gas soon,after they leave the pump and before the gas is cooled in the condenser.I also prefer to cool the oil after it has been thus exposed to heat andbefore it is returned to the pump.

If there be in the apparatus as a whole, as is usual, a separating-tank,orits equivalent, into which the whole charge of gas and oil from thepump is discharged, and to the bottom of which the oil drops, I place inthe bottom of such tank a coil heated by steam. The heat from this coilwill expel some of the gas from the oil, and this gas will go off withthe gas discharged from the pump into the pressure side of the apparatusand be cooled in the condenser, adding to the whole quantity ofcompressed gas that additional quantity which is driven off from the oilby heating the oil. The oil,after this heating and before it returns tothe pump, is, by preference, cooled by water in the usual apparatus orin other suitable known manner; or I may heat the oil in a coilpipe orkettle after it leaves the separatingtank, provided the cavity in whichit is heated is not open to the air,and is in some way connected to thepressure side of the apparatus, so

that the gas separated by heat will be introduced into the pressure sideof the apparatus,

the gas thus driven from the oil being subsedriven off by the subsequentheating of the oil my process appears to me to work, so far as effect isconcerned, much to the same advantage that would follow from the use ofan oil which wouldabsorb no gas. Such an oil is not yet known; but myprocess is designed for securing advantages similar to those which wouldresult from the use of such oil ifit were known.

The oil may be heated to drive off the gas after the oil has been cooledin the presence of gas and separated mechanically therefrom,provided thegas thus driven off is conducted to the pressure side of the apparatus;but this is an inferior way of working my process.

I have throughout this description used the word heating withoutspecifying any certain temperature, because different degrees of heatwill be required for different oils,.and because the degree ofheat willbe in some measure dependent upon the temperature at which the oilleaves the compressing-pump and also upon the boiling-point of theparticular oil used; but I can define generally the degree of heat to beapplied to the oil by stating that it must be greater than that at whichthe oil leaves the compressing-pump and less than that at which the oilboils.

I claim- 1. The improvement in the refrigerating process hereindescribed, which consists in heating the oil after it has been expelledfrom the pump, and conducting the gas driven off by such heating intothe pressure side of the apparatus, said heating being performed afterthe oil has been partially or wholly separated mechanically from the gasand before the oil is returned to the pump.

2. The improvement in the refrigerating process herein described, whichconsists in heating the oil after its expulsion from the pumpandsubsequentto mechanical separation from the gas,and the cooling ofsuch oil after it has been heated, the gas driven off by the heating,and prior to the cooling of the oil being conducted to the pressure sideof the apparatus.

GEO. F. MEYER.

\Vitnesses:

W. W. BAILEY, H. W. GUERNSEY.

